Flaring tool for hollow workpieces

Abstract

A flaring tool (1) for hollow workpieces having a basic tool body (2) with an expanding mandrel (13), which can be displaced by means of a drive. A supporting device (5) concentrically surrounding the expanding mandrel with an exchangeable expansion head (6) which has radially movable expanding jaws (14) located in a screw cap (16). The supporting device (5) is placed in the basic tool body (2) and can be moved longitudinally by means of a threaded extension (8) in the direction of the (A--A) axis of the expanding mandrel (13), and has an annular flange (11) which serves as a stop (10) for the expansion head. The supporting device (5) is fixed opposite the basic tool body (2) by means of a stopping device. In order to achieve a simple, reliable and reproducible set-up the supporting device (5) has in its annular flange (11), in a circle placed concentrically to the (A--A) axis, index boreholes for an index pin (29), located in the basic tool body (2).

What is claimed is: 
     
       1. Flaring tool for hollow, in particular for cylindrical hollow workpieces, comprising: a basic tool body, an axially displaceable expanding mandrel with a tapered end, and a supporting device, concentrically surrounding the expanding mandrel, for an exchangeable expansion head, having a drive with the help of which the expanding mandrel can be displaced against the expansion head at a predetermined stroke, the expansion head comprising a screw cap, which can be mounted on the supporting device and a set of expansion jaws which can be guided radially inside the screw cap, the supporting device being placed by means of a threaded extension in the direction of an (A--A) axis of the expanding mandrel in the basic tool body and being displaceable in longitudinal direction, and which supporting device has an annular flange serving as a stop for the expansion head, and a stopping device which acts on a displacement movement of the supporting device opposite the basic tool body, the supporting device having index boreholes placed in the annular flange in a concentric circle to the (A--A) axis, and an index pin which is located in the basic tool body, axes of the index boreholes and the index pin running parallel to the (A--A) axis of the expanding mandrel. 
     
     
       2. Flaring tool according to claim 1, in which the index pin has the shape of a stepped cylinder with a first and a second cylinder surface, which are arranged coaxially to each other forming a ring shoulder, and together with which the index pin is located in complementary coaxial tapholes in the basic tool body, and which tool includes a prestressed pressure spring located between the bottom of the taphole with the larger diameter and the ring shoulder and index pin with a cylinder surface with a larger diameter engaging in the index borehole of the annular flange. 
     
     
       3. Flaring tool in accordance with claim 1, in which the index pin protrudes from the basic tool body with a cylinder surface with a smaller diameter, and the index pin (29) having a sliding key being at the end of this cylinder surface. 
     
     
       4. Flaring tool according to claim 3, in which the basic tool body has two bearing blocks having a slit therebetween and in which the sliding key is guided in the slit between two bearing blocks of the basic tool body, secured against twisting turning, and protrudes from the slit.